Records of Humber Conservancy and the Humber Ports (Records deposited by Associated British Ports and its Predecessors) > Humber Conservancy > Publications produced, or acquired by the Humber Conservancy Board > Notices to Mariners issued by the Humber Conservancy Board or the Naval Authorities > Notice to Mariners: Temporary withdrawal of Middle Whitton Lightship and substitution of Light Float (Upper Humber)